Abstract Body

High incidence of HCV infection has been reported among high risk MSM. Current guidelines recommend that these individuals should be screened at least once a year with ALT and anti-HCV antibodies. Our aim was to assess the sensitivity of the different tests for early diagnosis of acute hepatitis C in high risk MSM.

In the ANRS IPERGAY PrEP trial among high risk MSM, a 3rd generation (3thG) antibody immunoassay (EIA ARCHITECT HCV Ab®, Abbott) was used for HCV diagnosis at screening and if ALT (performed every 2-months) ≥ 2.5 times the upper limit of normal. In patients with a positive EIA, we used stored sera to perform the following tests at the date of diagnosis and at previous visits (until HCV RNA was negative): antibodies (EIA 3thG ARCHITECT Anti-HCV, Abbott), rapid tests for detection of HCV antibodies (OraQuick® and Toyo®), plasma HCV RNA (AmpliPrep/COBAS® TaqMan® HCV Test, Roche and Xpert® HCV Viral Load, Cepheid), and the antigen immunoassay (EIA ARCHITECT HCV Ag®, Abbott). We evaluated the sensitivity of each test, including ALT, for the diagnosis of acute hepatitis C. HCV subtype was determined for each patient.

From March 5, 2012 to June 30, 2016, among 428 enrolled participants , 14 were diagnosed with HCV infection including one co-infected with HIV, with a median follow-up of 2.1 years (IQR: 1.5-2.8). One case was diagnosed at enrollment and 13 during follow-up, leading to an HCV incidence of 1.40 per 100 person-years (95%CI: 0.74-2.39). Phylogenetic analysis identified HCV genotype 1 in 6 patients (43%), type 3 in 1 (7%) and type 4 in the remaining 7 (50%). Stored sera were available in all 14 cases at diagnosis. At previous visit, which occurred within a median of 2 months earlier (IQR: 1.5-2), stored sera were available for most patients for EIA 3thG, HCV RNA Roche and ALT (Table). On the visit before the first positive HCV-antibodies, among 12 patients who were tested with both HCV RNA (Roche) and ALT, 7 had an HCV RNA detectable and no increased ALT (p=0.008 McNemar’s test).

The HCV antigen immunoassay and plasma HCV RNA test were positive within a median of 2 months before the detection of antibodies and ALT elevation, when patients were asymptomatic. These tests should be used in high risk MSM for early diagnosis of acute HCV infection and prevention of transmission.